Drill.



W. H. WAKFER.

DRILL.

AF PLICATION FlLED FEB. I4, 1914. I

' Patented Jan. 25,1916.

2 SHEETS-SHEET l.

W. H. WAKFER.

DRILL.

APPLICATION FILED FEB. 14, I914.

Patented Jan. 25, 1916.

2 SHEETS-SHEET 2.

See

' dal formation.

ving

WILLIAM HENRY TO SAMUEL PIECE, OF WALLINGTON, ENGLAND.

DRILL.

Specifleation of Letters Patent.

Patented Jan. 25, 1916.

Application filed February 14, 1914. Serial No. 818,890.

I To all whom it may concern:

IWAKFER, a subject of the King of Great Britain, and resident of 67Whitworth road, South Norwood, in the county of Surrey, England, haveinvented new and useful Improvements in Drills, of which the followingis a specification.

This invention comprises improvements in and relating to drills, bitsand like appliances for boring in earth, rock and the like.

The invention has for its object to improve the cutting or boringcapacity of these instruments, to lessen the cost of the upkeep of thetools of this character, and generally to increase the life andeiliciency of such tools while at the same time reducing the laborinvolved in the manufacture and handling of them.

Breakages frequen'tlyoccur, owing to the drills losing guidance whenentering say a fissure in hard rock, or to other causes, the resultbeing that the drills jump or get out of true alinement and-becomesubjected to seriousstresses, with consequent fractures which arerendered all the more possible by the employment of unsuitable steel, orimperfect tempering. Now, according to this invention, the cutting endof the boring head or bit is fitted with a center bit, or central guidepoint,lwhich bit or point extends beyond the cutting end and. is formedwith cutting edges. The main boring head or bit may be of the winged orother cross section type, and may be readily attachable to anddetachable from the tool bar. The head may be hollow for the whole of'its length, and the tool bar also may be hollow if desired. With awinged head .or bit of this nature the cutting edges would be producedby suitably forming the end faces of the wings or other suitableformations. Bits of so-called X-section or +-section may be used withadvantage but heads or bits havanynumber'of wings may be employed, orthe bits may be of prismatic and pyrami- Ihe invention will be describedwith reference to the accompanying drawings m' which a Figure 1 shows inelevation one form of boring head having tapered side wings and aremovable center bit in position thereon;

Fig. 2 is a plan of Fig. 1 with the center bit removed; Fig. 8' shows atool bar. in elevation; Figs. 4 and 4", are respectively a sideelevation and plan of the center bit removed from the boring head; Fig.5 shows in front elevation, Fig. 5 in side elevation and Fig. 5 in plana modified construction of the center bit; Figs. 6 and 7 are viewscorresponding to Figs. 1 and 2 of a modified construction and Fi 8 is aplan of the center bit shown in ig. 6; Figs. 9, 10, and 11 are viewssimilar to Figs. 6, 7 and 8 respectively of a further modifiedconstruction; Figs. 12, 13 and 14 are also views similar to Figs. 6', 7and 8 respectively of a still further modified construction in which theboring head and center bit are formed with helical wings; Figs. 15, 15and 15 are views corresponding to Figs. 5, 5 and 5 respectively'of afurther modified construction'of removable center bit.

A- hollow tubular head 1 of say, hine inches in length may as shown inFigs. 1 and 2 be formed with three radial wings 2 arranged at equaldistances apart around said head or the said head 1 may be formed withfour wings 2 so angularly disposed as to produce the so-called +-section as shown in Figs. 6 and 7 or X-section as shown in Figs. 9 and 10or other section. The wings 2 are tapered from one end of the head tothe other so that the distance across from tip to tip of opposite wingsmay be, say, two inches and seven eighths at the cutting end and twoinches, more or less, near the rear end. lhe bore of this hollow head 1is preferably tapered at the rear endas at 1 to receive the similarlytapered end 3 of the tool bar, see Fig. 3, or both may be threaded. Thetaper employed is preferably that known as the Morse taper. The wings 2may \as shown in Figs. 1, 6 and 9, merge into a tubular portion orsocket at the rear end of the head 1. Thecutting edges 4 of the tubularhead 1, which edges may be inclined to the longitudinal axis as shown inFig. 1 or perpendicular thereto as in Figs. 6 and 9 may be formed bygrinding or otherwise fashioning the ends of the wings 2 and theportions of the head- 1 forming radial continuations thereof to anapproximate V-shape, and the upper end of the said head may be formedwith V or other shaped cut ting edges between the said wings 2 as at 5,Figs. 6 and 7. The center bit preferably consists of a tapered orconical shank 6 adapted to be driven into the front end of the bore ofthe head 1 and may have a threebit is formed withfour quadrangular sidessided pyramidal end 7 formed on the shank, 17 increasing in width fromthe r lower to or on a short prismatic portion 8, Fig. 6, the theirupper ends these sides 17 being preferfaces of which are preferablyhollowed out, ably hollowed out as at 19 Figs. 9 and 11.

5 as shown. Longitudinal grooves 10, Figs. The upper end of this bit isformed as a 70 v 1 and 5 may be formed in the shank 6 to pyramid havingfour faces 18, a central permit fluid, air or steamto pass to the facespoint being thereby formed, where the said of the bit whenahollow toolbar isemployed. faces ,meet at the center of the bit. Ob- In theconstructions of center bit shown in viously the center bit may bearranged so i 1, 4, and 4 and. Figs. 5, 5 the end that its cutting edgesare opposite, or in 75' of the bit forward of the tapered shank 6"alinement with respective cutting edges on I is so formed as to mergefrom circular cross the head. section into a cross section of flatell(iiptical-' If desired the side faces of the center bit form, thedimension across the major iamemay be flat and not hollowed or grooved,-ter. of which is greater than the largest the shank 6 only being groovedfor the pas-- 80 diameter of the shank 6,. The center bit is sa e offluid. formed with V-shaped cutting edges 9, y forming the head taperedfrom the which are downwardly inclined from the cutting end toward therear, the tool is axis of the bit thus providing two radial enabled towork easily even when the head cutting edges and a central point -to thepenetrates a' considerable distance into the 85 cutting end. rock. Aftera tapered head having for The center bit shown in Figs. 1, {1 and f?example a cutting end two inches and sevendifi'ers only slightly fromthat shown in eighths across or in diameter has been used Figs. 5, 5 and5 in that the rear and foron a bar of, say, two feet in length, it mayWard faces of the bit Shown g 4 be knocked off and re-sharpened, ifneces- 90 and 4 are flattened asat 11 Fig. 4*, while sary, and owing tothe wear and tear and the the bit shown in Fig. 5 has the narrow sidessharpening, the length of the head will be thereof flattened as at 12.reduced so that the cutting end is then only Figs, 15, 15 and 15 show acenter bit of say two 'andthree-quarter inches across or somewhatconical formation, the port1on'13 thereabout in diameter. The head maynow 95 between the shank 6 and the upper or cutbe used upon a bar sayfour feet in len th ting end being conical, the larger and upper andafter becomin further worn and a ter end of this conical part beingbeveled upon being re-sharpene the cutting end, will be opposite sidesas at 14. A groove 15 is reduced still further, for example to twoformed acrossthe center of the upper end of inches and five-eighths orapproximately so *the bit in a direction at right angles to the across,or in diameter, when it could be used direction of the bevel thusdividing the cut.-- upon a bar say six feet in length, and so on. tingend of said bit into two substantially The rear end of any cutting headmay be chisel shaped cutters, the said groove 15 exformed with a;tapered socket or may be tends longitudinally on opposite sides of theadapted for being secured to the bar by pin- 105 bit, the lower ends ofthe grooves 15 joining ning, keying or screwing as will be readilygrooves 15 in the shank 6, whereby fluid understood. from a hollow toolcan passto the inner The use of the center bit or point enables faces ofthe cutting edges, wh lelongitud nal the head to produce a hole having adiameter 5 grooves 16, formed in the bit in a vertical correspondingwith or verylittle greater 110 plane containmgthe axis and at rightangles than the diameter of, or maximum distances to the plane passingthrough the grooves 15, across, the cutting end of the head, andcommunicate with the outer faces of the nevertheless the head will workeasily'and I cutter, and allow the fluid to have access freely in suchhole as the true direction thereto. Pins, keys or the like may bethereof is preserved owing to the action of 115 driven into suitableperforations formed in the center bit which, while preserving the theparts for securely coupling the center bit true alinement, also relievesa portion of the to the head and the latter to the tool bar. stress onthe boring or cutting head owing For example key slots 1 Fig. 9 may beto the fact that the cutting area of such head formed in the head and aslot 1 for a driver is reduced. 120 or releasing wedge may also beformed. All The center bit when worn or dama ed tapers used arepreferably of the Morse vacan be replaced without much loss of timeriety. In some cases it may be desirable for and at very little expenseand the removal the center bit to have the same number of 'of the centerbit can be facilitated by formsides and cutting edges as the number ofing therein a transverse slot for the recep- 12 wings or cutting edgespossessedby the bo rtion of a suitable prizing tool or the like. inghead. Such a construction 1s shown in The refettling and re-sharpeningof the head F g. 9 in which the boring head is formed is alsoaccomplished in a simple manner and with four radial wings 2 having attheir at very little expense and a great savin is upper ends cuttingedges .4, and the center thus eflected Whenthe repairing of the improvedtool is compared with the repairing of long bar tools as at presentused, because the latter involvelmuch loss of time and 1abor in carryingthem to the forge to be refettled and are difficult to handle during theoperation of re-fettling and re-sharpening them. The toolshereinbeforedescribed are primarily intended for use in percussive or hammer drills,but in order to further enhance the general utility of the improvedtools, both the center bit and the head may be so fashioned that theymay be used for a rotary drill. For this purpose both the center bit andcutting head may have a spiral or helical formation or may beconstructed as shown in Figs. 12 to 14 in which the tubular head 1 isformed with helical wings 20 the upper ends of which are so shaped as topresent radial chisel-shaped cutting edges 21, and the center bit ispreferably formed with-four cutting wings 22 the forward or leadingfaces of which are radial while the rear or following faces arehelically curved. The spiral or helical devices of the head 1' may becontinued along the tool bars or rods, and for exceptional depths anynumber of these tool bars or rods may be connected together by means ofinternally tapered and pinned, keyed or screwed sockets or othersuitable sleeves, sockets or coupling devices. The sleeves or socketspreferably have a. helical formation externally to continue the ejectingaction of the other helical parts above described. The sleeves, socketsor coupling devices may have any suitable cross section and the partsare secured together by pins, keys, or the like. The center bits shownin the drawings are not necessarily for use only with the boring headsin connection with which they are shown, as,

different forms of center bit may be used with the same head.

I claim 1. Drills, bits and the like for boring in earth, rock and thelike, comprising in combination a tubular boring head, a plurality oflongitudinally disposed projections on said head, a plurality of cuttingedges formed on one end of said head and along the ends of saidprojections, a center bit, and a tapered shank on said bit adapted to bedriven into the cutting end of said tubular head, said shank beingformed with axially directed recesses adapted to communicate between theinterior of the tubular head and the atmosphere when said bit is inposition substantially as and for the purpose set forth.

2. Drills, bits and the like for boring in earth, rock and the like,comprising in combination a tubular boring head, a plurality oflongitudinally disposed projections on said head, a plurality of cuttingedges formed on one end of said head and along the ends of saidprojections, a center bit, a shank thereon adapted to be secured in thecutting end of said tubular head, said shank being formed with recessesextending into the faces of the bit, said recesses being adapted tocommunicate with the interior of the tubular head and the atmospherewhen said bit is in position substantially as set forth.

\VILLIAM HENRY WAKFER.

Witnesses:

Eorrrr WILSON, P. PHILLIPS.

